<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body class="fdcolumn flex">
    <header class="header"></header>
    
    <main class="fdcolumn flex">

        <input type="text" placeholder="🔍搜索" >
        
        <div id="concern1">
            
        </div>
    </main>
</body>
</html>